code: def test_unary_nullable(self):
      df = pd.DataFrame(
          {
              "a": pd.array([1, -2, 3, pd.NA], dtype="Int64"),
              "b": pd.array([4.0, -5.0, 6.0, pd.NA], dtype="Float32"),
              "c": pd.array(
                  [True, False, False, pd.NA], dtype="boolean"
              ),
              # include numpy bool to make sure bool-vs-boolean behavior
              #  is consistent in non-NA locations
              "d": np.array([True, False, False, True]),
          }
      )
  
      result = +df
      res_ufunc = np.positive(df)
      expected = df
      # TODO: assert that we have copies?
      tm.assert_frame_equal(result, expected)
      tm.assert_frame_equal(res_ufunc, expected)
  
      result = -df
      res_ufunc = np.negative(df)
      expected = pd.DataFrame(
          {
              "a": pd.array([-1, 2, -3, pd.NA], dtype="Int64"),
              "b": pd.array([-4.0, 5.0, -6.0, pd.NA], dtype="Float32"),
              "c": pd.array(
                  [False, True, True, pd.NA], dtype="boolean"
              ),
              "d": np.array([False, True, True, False]),
          }
      )
      tm.assert_frame_equal(result, expected)
      tm.assert_frame_equal(res_ufunc, expected)
  
      result = abs(df)
      res_ufunc = np.abs(df)
      expected = pd.DataFrame(
          {
              "a": pd.array([1, 2, 3, pd.NA], dtype="Int64"),
              "b": pd.array([4.0, 5.0, 6.0, pd.NA], dtype="Float32"),
              "c": pd.array(
                  [True, False, False, pd.NA], dtype="boolean"
              ),
              "d": np.array([True, False, False, True]),
          }
      )
      tm.assert_frame_equal(result, expected)
      tm.assert_frame_equal(res_ufunc, expected)
  
file_path: pandas/pandas/tests/frame/test_unary.py
imports: from decimal import Decimal
  import numpy
  import pytest
  from pandas.compat.numpy import np_version_gte1p25
  import pandas
  import pandas._testing
label_desc: Use image node_id 11 for calling the TestDataFrameUnaryOperators obj's underlying member method code with example usage: obj.test_unary_nullable() without return types